In today's information age, an ever-increasing number of devices are being interconnected over communication networks. While most networked devices have traditionally been general-purpose computers and related peripherals, more and more networked devices are special-purpose devices. It is getting to the point where just about anything can and is being coupled to communication networks. For convenience, a device (other than a computer or workstation) that is capable of being coupled to a communication network and consuming network services is referred to hereinafter as a data appliance (DA).
The sheer ubiquity of these newer DAs will make them more accessible and more idealized for specific purposes than general-purpose computers. Thus, these newer DAs can be expected to attract a higher degree of usage, and by a larger portion of the general population. These factors combine to place additional strains on communication networks, which will be hard pressed to provide sufficient bandwidth and services to the DAs as the number of DAs increases. Deficiencies in existing communication networks include insufficient wiring for coupling the DAs to the communication networks, too few router and LAN ports for supporting the DAs, and insufficient address space.
Traditional solutions to such deficiencies include such things as installing additional wiring for coupling the DAs to the communication networks, layer 2 bridging to reduce the number of router and LAN ports for supporting the DAs, and layer 3 switching to use fewer layer 3 addresses. The shared access mechanisms, such as layer 2 bridging and layer 3 switching, have certain limitations, including providing the bridged/switched DAs with unequal access to the communication network compared to other DAs, preventing the DAs from being logically separated (e.g., for layer 2 or layer 3 VLANs), requiring that the DAs use the same protocol and reside in the same subnet, and causing various management and security problems. Furthermore, installing additional wiring for coupling the DAs to the communication networks, layer 2 bridging to reduce the number of router and LAN ports for supporting the DAs, and layer 3 switching to use fewer layer 3 addresses become prohibitive as the number of DAs increases.